Perl Module Creation & Usage - Undefined subroutine - perl

Question

I am trying to create & use modules in a new script I'm doing but I'm not familiar with modules yet.
I've been following some tutorials, and even if I have the "almost" exact same code as in the tutorial, it doesn't work and when I run my test-script I get the following error:
Undefined subroutine &main::func1 called at ../../bin/fftg.pl line 21.
Here is my main script :
#!/usr/bin/perl
# ......
# comments here
# ......
use strict;
use warnings;
use File::Basename qw(dirname);
use Cwd qw(abs_path);
use lib dirname(dirname abs_path $0) . '/lib';
use FFTG::PID qw(:DEFAULT);
print func1(10,20);
and here is the module, created as file lib/FFTG/PID.pm :
package PID;
use strict;
use warnings;
use Exporter;
our $VERSION = 1.00;
our #ISA = qw(Exporter);
our #EXPORT = qw(&func1 &func2); # I tried all lines without &
our #EXPORT_OK = qw(&func1 &func2); # I tried all lines without &
our %EXPORT_TAGS = ( DEFAULT => [qw(&func1)],
Both => [qw(&func1 &func2)]);
sub func1
{
my ($x, $y) = #_;
return $x + $y;
}
sub func2
{
return "tata\n";
}
1;
what am I doing wrong please ?
I tried to load the thing using :
use FFTG::PID qw(:DEFAULT);
use FFTG::PID;
use FFTG::PID qw(funct1);
use FFTG::PID qw(&funct1);
nothing works (same error)
I also tried to modify the module, modifying these lines removing or adding the & :
our #EXPORT = qw(func1 func2);
our #EXPORT_OK = qw(func1 func2);
same problem
any hints ?
my folders & files are :
MIF/root#sm1p0003vmo /wminfs/mc/projects/FFTGv2: pwd
/wminfs/mc/projects/FFTGv2
MIF/root#sm1p0003vmo /wminfs/mc/projects/FFTGv2: ls -al bin/fftg.pl
-rwxr-x--- 1 root root 545 May 18 09:49 bin/fftg.pl
MIF/root#sm1p0003vmo /wminfs/mc/projects/FFTGv2: ls -al lib/FFTG/PID.pm
-rw-r----- 1 root root 344 May 18 09:37 lib/FFTG/PID.pm
MIF/root#sm1p0003vmo /wminfs/mc/projects/FFTGv2:
thanks
regards,

Answer 1

There are a few errors, and a few things that can be done better.
The module name needs to match its (relative) location, so: package FFTG::PID;
There can be no & when listing subroutines for EXPORTs in the module; those should be names and the & isn't a part of the name. From use pragma (my emphasis)
Imports some semantics into the current package from the named module
All-caps names are a risky idea as they may be taken, and DEFAULT cannot be used here
It is generally a good advice to use #EXPORT_OK, and not #EXPORT.
Finally, the line that sets up lib is asking for trouble. Use FindBin.
Package lib/FFTG/PID.pm
package FFTG::PID;
use strict;
use warnings;
use Exporter qw(import);
our $VERSION = 1.00;
our #EXPORT_OK = qw(func1 func2);
our %EXPORT_TAGS = (
default => [ qw(func1) ],
both => [ qw(func1 func2) ]
);
sub func1
{
my ($x, $y) = #_;
return $x + $y;
}
sub func2
{
return "tata\n";
}
1;
where I've also replaced the explicit setup of #ISA with the Exporter'simport method.
The main program
use strict;
use warnings;
use feature qw(say);
use FindBin qw($RealBin);
use lib "$RealBin/lib";
use FFTG::PID qw(:default);
say func1(10,20);
It prints a line with 30.